docs(devops): describe windows buildbot configuration

browser_patches/bots.md

@@ -0,0 +1,63 @@
+# Setting Up Build Bots
+
+This document describes setting up bots infrastructure to produce
+browser builds.
+
+We currently have 4 build bots that produce 6 builds
+- **[bot-linux]** Ubuntu 18.04 machine
+    - builds: `Webkit-Linux`, `Firefox-Linux`
+- **[bot-mac-10.14]** Mac 10.14 machine
+    - builds: `WebKit-mac-10.14`, `Firefox-Mac`
+- **[bot-mac-10.15]** machine
+    - builds: `WebKit-mac-10.15`
+- **[bot-windows]** Windows machine
+    - builds: `Firefox-win32`
+
+# bot-windows
+
+## Setting Up Host Machine
+
+### 1. Prepare machine to compile firefox
+
+Follow instructions on [Building Firefox for Windows](https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/Build_Instructions/Windows_Prerequisites). Get the checkout with mercurial and run "./mach bootstrap" from mercurial root.
+
+After this step, you should have `c:\mozilla-build` folder
+and `c:\mozilla-source` folder with firefox checkout.
+
+> **NOTE:** No spaces or quotes are allowed here!
+
+### 2. Install azure-cli
+
+Install [azure-cli](https://docs.microsoft.com/en-us/cli/azure/install-azure-cli-windows?view=azure-cli-latest) for windows using MS Installer
+
+### 3. Export "az" to the mingw world
+
+Run `cmd` as administrator and run the following line:
+
+```
+> echo cmd.exe /c "\"C:\Program Files (x86)\Microsoft SDKs\Azure\CLI2\wbin\az.cmd\" $1 $2 $3 $4 $5 $6 $7 $8 $9 ${10} ${11} ${12} ${13} ${14} ${15} ${16}" > "%SYSTEMROOT%\az"
+```
+
+This command will create a `c:\Windows\az` file that will call azure-cli with passed parameters (Not the most beautiful solution, but it works!)
+
+
+### 4. Provide CDN credentials to mingw env
+
+Edit `c:\mozilla-build\start-shell.bat` and add two lines in the beginning:
+
+```bat
+SET AZ_ACCOUNT_NAME=<account-name>
+SET AZ_ACCOUNT_KEY=<account-key>
+```
+
+change `<account-name>` and `<account-key>` with relevant keys/names.
+
+### 5. Checkout PlayWright to /c/
+
+Run `c:\mozilla-build\start-shell.bat` and checkout PlayWright repo to `/c/playwright`.
+
+
+## Running Build Loop
+
+1. Launch `c:\mozilla-build/start-shell.bat`
+2. Run `/c/playwright/browser_patches/tools/poll_build.sh`